Pin contact



April 196.5 J. E. ANTES 3,178,676

PIN CONTACT Filed Sept. 28, 1962 FIG. 2 a;

INVENTOR. JACK a. 44/75.:

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United States Patent 3,178,676 PIN CONTACT Jack E. Antes, Greenwich, Conn., assignor to Burndy Corporation, a corporation of New York Filed Sept. 28, 1962, Ser. No. 227,026 2 Claims. (Cl. 339252) This invention relates generally to a contact pin for use in plug and socket electrical connections and more particularly to an improved contact pin which carries a contact pressure maintaining spring.

Contact pins having pressure maintaining springs assembled to the pin body are known in the connector art. In some previously known pins, a complex pin body having a number of parts is required to assure proper spring retention. These pins often require hand assembly of the spring or spring parts to the pin body and are otherwise expensive to produce. In others, having a unitary body incorporating an integrally formed resilient portion, optimum resiliency and contact characteristics cannot both be obtained in a single pin. Pins of presently known design, of both separate and integral spring types, are generally not well adapted to miniaturization.

Accordingly it is an object of this invention to provide a pressure spring and contact pin assembly which may be conveniently produced in miniature size. Another object is to provide a miniature contact pin having an independently formed spring affixed thereto. Other objects are to provide a pin-spring assembly in which the pin may be economically formed of sheet material, which is readily adapted to either hand or machine assembly, and which may be produced in a form adapted for automatic processing.

These and other objects and advantages of this invention will be made more apparent by reference to the following description taken in conjunction with the attached drawings wherein:

FIGURE 1 is a perspective view of a contact pin and connected conductor, formed in accordance with this invention;

FIGURE 2 is a plan view of a contact pin and integral connecting strip;

FIGURE 3 is an elevation view of the contact pin of FIGURE 2 with the connecting strip removed;

FIGURE 4 is a partially sectioned view of the contact of FIGURE 3 assembled to a mating socket contact.

Referring now more particularly to the drawings, the pin may be seen to comprise a conductive body member having a spring member 12 affixed thereto. The body member has a cylindrical pin portion 14 which is adapted to be inserted into a bore 42 in a mating socket contact 40 (FIGURE 4), and an end portion 16 adapted to be mechanically and electrically secured to a conductor such as 50. A tab 32 cooperates with the end portion to form a stop for limiting the extent of insertion of a conductor therein. A longitudinal opening 18 is formed in the surface of the pin portion 14 running from the tip back toward the conductor end portion 16. An annular groove 34 in the outer surface of the body 10 may be provided to engage a detent in a mounting block (not shown) for securing the contact thereto.

Spring member 12 is substantially U-shaped, and has one leg 20 secured to the body and another leg 22 pcsitioned in radial alignment with opening 18. A resilient base portion 24 intermediate the two legs resiliently biases leg 22 outwardly away from leg 20 and permits it to be resiliently compressed into opening 18 by radial forces such as are caused by inserting the pin into a mating bore. Leg 22 is preferably arcuately bent to form an outwardly inclined portion 26 at its forward end, which serves as a lead-in and camming surface for engaging the entrance to a mating bore.

In the embodiment shown, spring leg 20 is secured to the body 10 byv staking or pinching the tip of pin portion 14 as shown at 80, to grip the spring leg. By fixedly securing one leg to the body the major portion of the spring is freed to be disposed externally with no sacrifice in reliability of retention or accuracy of positioning. The outer diameter of externally disposed base portion 24 may thus be made equal to the outer diameter of pin 14 or inner diameter of bore 42, to obtain a maximum radius of curvature and optimum spring resiliency in the smallest pin sizes.

The free end 28 of spring leg 22 is disposed within an opening 30 in the conductive body 10 to act as a guide for deflection of the spring, and to prevent snagging on other objects when the pin is handled apart from its socket. Mounting the spring in this manner leaves end 28 of leg 22 free for axial displacement to facilitate its fiexure when pressed into slot 13.

Spring member 12 is preferably formed of resilient conductive wire stock. Conductive body 10 may be formed, as in the embodiment shown, from a unitary strip of sheet metal cut into individual contact blanks. Formation of the blanks into the desired pin shape may be accomplished by any of the well known sheet metal bending and forming processes. The blanks may be cut out separately to form a plurality of independent contacts or they may remain interconnected by an integral selvage strip such as 36, provided with feed holes 38, to facilitate automatic forming, assembly, and utilization. If a continuous selvage strip is used, the individual contacts may be out free at any convenient point in the manufacturing or utilization process by means such as a standard sheet metal shear.

The invention has thus been described but it is desired to be understood that it is not confined to the particular forms or usages shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of the invention; therefore, the right is broadly claimed to employ all equivalent instrumentalities coming within the scope of the appendant claims, and by means of which objects of this invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects and accomplish these results.

I claim':

1. An electrical contact of the pin type, comprising: a body member formed of conductive sheet metal including a longitudinally extending tubular pin portion, having a tip at one end thereof, adapted to be inserted tip first into a mating receptacle contact opening; and a substantially U-shaped resilient spring member having a reversely bent portion and two leg portions extending therefrom; said spring member having one of said leg portions disposed within said tubular pin portion and fixedly attached to said body member, and said reversely bent portion projecting beyond the said tip portion of said body member for use as a lead-in during insertion of said pin portion into a mating receptacle contact.

2. An electrical contact in accordance with claim 1 wherein said one leg portion of said spring member is fixedly secured to said body member by a mechanically deformed section of said tubular pin portion at the tip portion thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,143,564 1/39 Lybarger et al. 339-252 2,689,337 9/54 Burtt et a1 339-275 X 2,794,964 6/57 Hoffman 339-276 FOREIGN PATENTS Germany. Germany. Great Britain. Great Britain. Great Britain. Italy.

M. I-IENSON WOOD, 1a., Primary Examiner.

15 JOSEPH D. SEERS, Examiner. 

1. AN ELECTRICAL CONTACT OF THE PIN TYPE, COMPRISING: A BODY MEMBER FORMED OF CONDUCTIVE SHEET METAL INCLUDING A LONGITUDINALLY EXTENDING TUBULAR PIN PORTION, HAVING A TIP AT ONE END THEREOF, ADAPTED TO BE INSERTED TIP FIRST INTO A MATING RECEPTACLE CONTACT OPENING; AND A SUBSTANTIALLY U-SHAPED RESILIENT SPRING MEMBER HAVING A REVERSELY BENT PORTION AND TWO LEG PORTIONS EXTENDING THEREFROM; SAID SPRING MEMBER HAVING ONE OF SAID LEG PORTIONS DISPOSED WITHIN SAID TUBULAR PIN PORTION AND FIXEDLY ATTACHED TO SAID BODY MEMBER, AND SAID REVERSELY BENT PORTION PROJECTING BEYOND THE SAID TIP PORTION OF SAID BODY MEMBER FOR USE AS A LEAD-IN DURING INSERTION OF SAID PIN PORTION INTO A MATING RECEPTACLE CONTACT. 